Gift & Zift
Intrafallopian transfer is a rarely used (about 2 percent of the time) method of assisted reproductive technology (ART), which helps women who are having infertility issues become pregnant. The process facilities fertilization by implanting harvested eggs and sperm into one of the fallopian tubes. In a variation on the procedure, an already fertilized egg is implanted.
Candidates for Intrafallopian Transfer
In order for an intrafallopian transfer to be effective, the woman must have at least one functioning fallopian tube and the man must have more than two million sperm in his ejaculate. To ensure that these two conditions are met, the woman usually has a hysterosalpingogram (an X-ray of the uterus and tubes using contrast dye) and a laparoscopy to confirm the absence of scar tissue around the fallopian tube. A sample of the man’s sperm is also obtained to assess the count.
Benefits of Intrafallopian Transfer
Intrafallopian transfer is a variation on In Vitro Fertilization (IVF); it has a similar success rate. Some women for whom In Vitro has been unsuccessful do better with intrafallopian transfer, perhaps because it more closely approximates natural conception. Another advantage of intrafallopian transfer is that conception is immediate.
The Intrafallopian Transfer Procedure
There are several steps involved in intrafallopian transfer. First, the ovaries are stimulated with hormones to produce several eggs. Once the eggs have been produced, they are harvested using ultrasound guidance through the vagina and then placed in a Petri dish with active sperm. One of two methods of implantation is then used.
Gamete Intrafallopian Transfer (GIFT)
GIFT is the most common type of intrafallopian transfer. During GIFT, the mixture of sperm and egg is immediately transferred into the woman’s fallopian tube so that fertilization can take place at its natural site. For patients having difficulty conceiving, the GIFT process increases the probability that fertilization will take place. Because the attempt at fertilization takes place in the fallopian tube, however, whether it has been successful cannot be immediately confirmed.
Zygote Intrafallopian Transfer (ZIFT)
ZIFT is similar to GIFT except that fertilization takes place outside that body. Once the egg has been fertilized in a Petri dish, the single-celled fertilized egg (zygote) is transferred into the fallopian tube laparoscopically. The difference between ZIFT and other reproductive techniques is that the fertilized egg is transferred before it develops into an embryo and that it is implanted in the fallopian tube, not the uterus.
Results of Intrafallopian Transfer
ZIFT is typically recommended for women who have gone through IVF several times without success. Because the fertilized egg if transferred directly into a fallopian tube, the procedure is also referred to as tubal embryo transfer (TET). ZIFT can be more successful than GIFT because with ZIFT, fertilization has already taken place at the time of implantation. ZIFT has the advantage over IVF because fewer eggs are used, lessening the risk of multiple birth. Nonetheless, for some women, GIFT is the only procedure acceptable because of their religious beliefs.